Method of preventing rusting of ferrous metal surfaces



Patented Jan. 9,1940

lemon or PREVENTING nus'rmo or rennous METAL sunrscns 'wmiamm. to TheAtlantic Refining comm. Philadelpbia, 2a., aoorporation of PennsylvaniaNo Drawing. Application November 20, 193'], SerialNo. 175,51:

1 Claim-f (oi.- iii-es) 7 held by the metal surface, probably by adsorp-The present invention relates to-a method for inhibiting or preventingthe rusting of ferrous metal surfaces, and particuiarb iron orsteefsurfaces which may be subjected to conditions nor- 5 mallyconducive to rusting. The present invention is particularly applicableto the prevention of. rusting of 'iron or steel sheets or plates, bars.tubes, wire, and articles fabricated from iron orsteel by 1 rolling,grinding or machining.

A principal object of this invention is the inhibition or prevention ofrusting of ferrous metal surfaces by the application thereto of a him ofoil invention are preferably hydrocarbon oils having 4 a SayboltUniversal viscosity'at 100 F. of at least 60 seconds, and substantiallyfree of constituents tendingto stain, corrode orv react with ferrousmetal surfaces. Hydrocarbon oils derived from paraflin base or naphthenebase petroleum, or oils 7 produced by solvent extraction, hydrogenation.or.

other means may be suitably employed. In general the oil component 'ofthe rust-preventing composition comprises about 90% or more of the '30composition.

The synthetic esters to be employed in conjunction with the hydrocarbonoil are preferably those derived by the reaction of aliphatic oraromatic alcohols or phenols with carboxylic acids, preferably saturatedcarboxylic acids having from about 8 to about 25. carbon atoms permolecule.

, Among the alcohols may be mentioned methyl alcohol, ethyl alcohol,propyl alcohol, isopropyl alcohol, the butyl alcohols, the amyl andhexyl 4 1! alcohols, cetyl alcohol, the glycols, glycerol, phenol,cresol, naphthol, benzyl alcohol and the like. The organic acids may beexemplified by caprylic acid, capric acid, undecylic acid, lam'lc acid,myr'lsticacidpalmiticacidmargaricacldstearie acid,.arachidic acid,cerotic acid, meli'ssie acid.

.the naphthenic acids. benaoic' acid, phthalic acid and the like.Quantities of the esters ofthe order of 1%,2%,5%.and 10%ormoremaybeadded to thehydrocarbonoilandtheadmixtureorsolution appliedto rustable metal surfaces by dipping.

entinventiomwhenappliedtoferrousmetolsurllfacaprovideafluidnlmwbichis'tenaciomlyoperations involving pressing, stamping,

Universal at 1". i

tion, and which is resistant to the penetration of moisture. Such filmsare non-drying and readily removable by wiping. washing with organicsolvents, soap solutions or other detergents. The

oil-synthetic ester compositions utilized in accordance with thisinvention do not have the dis-' advantages inherent in the use ofnatural oils. fats, fatty oils and mixtures thereof with hydro carbonoil, which have been employed heretofore as rust-proofing agents. Manyof the natural fatty oils are glycerides of unsaturated fatty acids, andwhen applied to metal surfaces in the undiluted state or admixed withhydrocarbon oil. form sticky or tacky films due to the oxidation and/orpolymerlzationof the unsaturated con stituents. 'I'hese tacky films aredimcult to remove, since the oxidized constituents arerelatively-insoluble in organic solvents and not readily removed 'bywater or detergent solutions. Furthermore, many of the fatty oilscontain varying amounts of free fatty acids which tend to corrode orstain the metal with which they come in contact. The fatty oils alsotend to become rancid, particularly when exposed in relatively thinfilms to the action of air. However, the synthetic esters employed inconjunction with bydrocarbon oil in accordance with this invention donot form sticky or gummy deposits upon the ,metal surfaces, do notoxidize nor polymerize, nor become acidic nor rancid, and are readilyremoved from metal surfaces.

The following examples will serveto further illustrate my invention Testpieces of polished, cold rolled steel were coated with therust-inhibiting compositions and exposed to the atmosphere (temperature77' E; humidity 100%) for a period of one week. The viscodty of the mineral oil component is given in seconds Saybolt rusting. V bodmsting.

ruding. Vcybodrustbig. Yam rutl 'mmtheaboveemmplesitwill'beseenthatthehydrocarbonoiLpersawasineifective'asa rust-inhibitor, whereas thehydrocarbon oil-synhibitingactionandpreventedrustingtoasatis- Amdsteelmind rusting. v

compositions showed a marked in- 10 higher.

factory extent. The rust inhibiting method of the present invention isparticularly adapted for the protection of iron or steel products whichmay be placed in storage under conditions normally conducive to rusting.

For brevity, herein and in the appended claim, the term viscoushydrocarbon oil" is to be understood to comprehend oils having a BayboltUniversal viscosity at 100 F. of 60 seconds or What I claim is: A methodof inhibiting rusting of a ferrous naphthenates.

WILLIAM K. GRIEBINGER.

